The EX-ACT tool
The EX-ACT (Environmental Externalities Accounting Tool) is FAO’s integrated appraisal system for assessing the environmental impacts of investments, programmes and policies in the Agriculture, Forestry and Other Land Use (AFOLU) sector. The tool provides a comprehensive framework to quantify and value environmental externalities, helping decision-makers identify trade-offs, compare intervention options, and design more sustainable and resilient agrifood systems.
EX-ACT combines the assessment of greenhouse gas (GHG) emissions, carbon sequestration, and biodiversity impacts, enabling users to evaluate both climate and ecological outcomes of project activities. Using internationally recognized scientific methodologies, the tool estimates the effects of land use change, agricultural practices, forestry interventions, infrastructure development and other project activities on environmental performance over time.
The climate assessment component applies IPCC-compliant methodologies to estimate changes in carbon stocks and GHG emissions associated with project implementation. These results support climate-smart planning, monitoring, reporting and access to climate finance.
The biodiversity assessment component evaluates the impacts of project activities on ecosystems and species through the effects of land use change, habitat fragmentation, infrastructure development and human encroachment on biodiversity, expressed through the Mean Species Abundance (MSA) indicator.
The EX-ACT (Environmental Externalities Accounting Tool) is FAO’s integrated appraisal system for assessing the environmental impacts of investments, programmes and policies in the Agriculture, Forestry and Other Land Use (AFOLU) sector. The tool provides a comprehensive framework to quantify and value environmental externalities, helping decision-makers identify trade-offs, compare intervention options, and design more sustainable and resilient agrifood systems.
EX-ACT combines the assessment of greenhouse gas (GHG) emissions, carbon sequestration, and biodiversity impacts, enabling users to evaluate both climate and ecological outcomes of project activities. Using internationally recognized scientific methodologies, the tool estimates the effects of land use change, agricultural practices, forestry interventions, infrastructure development and other project activities on environmental performance over time.
The climate assessment component applies IPCC-compliant methodologies to estimate changes in carbon stocks and GHG emissions associated with project implementation. These results support climate-smart planning, monitoring, reporting and access to climate finance.
The biodiversity assessment component evaluates the impacts of project activities on ecosystems and species through the effects of land use change, habitat fragmentation, infrastructure development and human encroachment on biodiversity, expressed through the Mean Species Abundance (MSA) indicator.
EX-ACT aims to:
- Quantify climate and biodiversity impacts of investments, programmes and policies in the AFOLU sector.
- Provide decision-makers with science-based indicators to support evidence-informed planning and investment decisions.
- Capture environmental externalities that are not reflected in conventional financial analyses.
- Facilitate the integration of climate and biodiversity considerations into project design and policy development.
- Support countries and institutions in preparing investment proposals and accessing funding from international financial institutions and environmental finance mechanisms.
Methodological basis
The climate component of the Environmental eXternalities ACcounting Tool (EX-ACT) is primarily based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, the 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands, and the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, complemented by additional peer-reviewed scientific literature where required.
Additional methodological sources include Lal (2004) for farm operations, inputs, transport and irrigation systems, UNFCCC (2021) electricity emission factors, ADEME (2020/2021) infrastructure emission factors, and sector-specific references for fisheries, aquaculture and coastal ecosystems. More information can be found under the "training materials" and "publications on EX-ACT" sections.
The biodiversity component of EX-ACT is based on the Global Biodiversity (GLOBIO) Model, developed by the PBL Netherlands Environmental Assessment Agency.
Introduction to the new tool
Do you want to know more about the tool and its use? You can consult training materials and publications from the menu on the sidebar. Additionally, please feel free to contact us at ex-act@fao to schedule a discussion.